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post #1 of (permalink) Old 07-23-2002, 06:31 PM Thread Starter
 
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Engine timing problems - help!

Ok, here's the problem I have.

Since I put the motor in I haven't been able to get a timing light so it has sat where I initally set it by ear 3-4 weeks ago.

Now I finally get a light and tach and I set the idle speed via the throttle set screw, and go to set the timing and I get about 20+deg advance. When I bring it down to eight it bogs out real bad and idles way down.

The q-jet on the motor (rebuilt targetmaster) is from my old motor(78 LS9) and was new 3 years ago.

I asked at few buddies at work and they suggested it might be the idle mixture (as did the sandman) and they said I should set it like this..

1. Fully warm motor up and make sure choke is fully disengaged.
2. Check vacuum (can I do this off the PVC vacuum port off the carb??) and see if it is good or not.
3. He suspects my idle screws are turned to far out so his recomendation was to turn the mixture screws all the way in, then 1.5 turns out each.
4. Carefully back out the mixture screws until the vacuum is where it should be.
5. Set idle speed with throttle screw
6. Check timing and see if that works.

Does this sound good??

Should I drop the timing back to 8 degrees first before I do this, or leave it at 20 where it runs half decent?

Any help is appreciated.
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post #2 of (permalink) Old 07-23-2002, 06:44 PM
 
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Re: Engine timing problems - help!

<font face="Times New Roman">
<font color=green>You are disconnecting the vacuum advance to the distributor from the carb and plugging it, right?
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post #3 of (permalink) Old 07-23-2002, 06:56 PM Thread Starter
 
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Re: Engine timing problems - help!

Yes I forgot about including that part of the operation. I had it disconnected when I got 20+deg BTDC yesterday.
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post #4 of (permalink) Old 07-24-2002, 04:02 PM
ratlover
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Re: Engine timing problems - help!

20 degres inital[img]images/icons/shocked.gif[/img] Does it ping under load?(or have you not driven it yet?) You shure you timed it right and the light is accurate? Might recheck it with another light before you jack with the carb.....you dont have an msd box do you? Just HEI right?
post #5 of (permalink) Old 07-24-2002, 04:54 PM
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Re: Engine timing problems - help!

you did try Top Dead Center on number one cylinder didnt you? that works everytime.
post #6 of (permalink) Old 07-24-2002, 06:14 PM Thread Starter
 
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Re: Engine timing problems - help!

Ratlover - yes 20+ deg initial at idle. big time pinging under load. It was set to this by ear cause that's where it ran half decent when I put the motor in.

Last night I screwed the mixture screws all the way in then backed them out until I got the most rpm and vacuum. Then I set my idle speed to 700 and set the timing to 8 deg advance.

Seemed to run much better, no more pinging what so ever, but I think its running lean big time now. I'm going to advance the timing another 2 degrees and richen the idle mixture up today and see how it runs.

BTW is screwed out rich or screwed in rich on the q-jet??

Also got a HUGE increase in brake pedal feel now, stiff as a rock.
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post #7 of (permalink) Old 07-24-2002, 10:23 PM
 
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Re: Engine timing problems - help!

as allneedle valves are the same i would assume that screwed in is lean...this may be inaccurate, but i am pretty confident its accurate
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